Spoolhead project was effort to enable RepRap 3d printers to print and embed metal wire in plastic prints. They made some progress but the project is not active at the moment.
http://reprap.org/wiki/SpoolHead
http://spoolhead.blogspot.com/
Project final report in PDF (2010): http://reprap.org/mediawiki/images/2/25/SpoolHead_FinalReport.pdf
http://reprap.org/wiki/SpoolHead
http://spoolhead.blogspot.com/
Project final report in PDF (2010): http://reprap.org/mediawiki/images/2/25/SpoolHead_FinalReport.pdf